Gaps in In-situ and Ex-situ Conservation of Threatened Medicinal Plant Species of Sri Lanka; Towards Their Effective Conservation

Abstract Sri Lanka is a country rich in biodiversity, harboring 1476 plant species with medicinal values, 307 of which are threatened. These medicinal plants have long been a valuable resource in traditional medicine, reflecting a well-documented historical legacy. However, the fact that 20% of these medicinal plants are listed as threatened poses a major conservation challenge. This study addresses the need for effective conservation strategies for threatened medicinal plants in Sri Lanka. The study focuses on using Geographic Information System (GIS) technology to monitor the distribution of threatened medicinal plants in Sri Lanka, prioritizing the species and areas for conservation and needs for ex-situ conservation. Using comprehensive datasets on the distribution of threatened medicinal plants from scientific literature, institutes, and herbarium collections, we assessed the priority areas within existing protected areas for in-situ conservation and ex-situ conservation status in Government Medicinal Plant Gardens. The research highlights the significance of Sinharaja rainforest and Peak Wilderness Sanctuary (Sri Padaya) as important protected areas with high species richness, housing 68 and 83 threatened medicinal plants respectively. Our findings show that a substantial proportion of threatened medicinal plants are distributed outside of protected areas, highlighting the need of establishing new protected areas as well as expanding the existing protected areas to conserve these unprotected threatened medicinal plants. Ex-situ conservation efforts were found to be crucial, especially for overexploited and endangered species. Our study highlights the importance of integrating GIS technology into conservation management to ensure the effective conservation of Sri Lankan medicinal plants for future generations.